Fluid-gage.



M. MARTIN.

FLUID GAGE.

APPLICATION FILED JULY so, 1909.

1,003,404. Patented sept. 12,1911.

UNITE site?.i

FLUID-GAGE.

Specification of Letters Patent.

Patented Sept.. i12, 1911..

i Application led July 30, 1909. Serial No. 510,429.

To all whom it may concern:

Be it known that 1, MORRIS MARTIN, a citizen ofi the United States,residing at Malden, county of Middlesex, and State of Massachusetts,have invented an Improvement in Fluid-Gages, of which the followingdescription, in connection with the accompanying drawing, is aspecification, like letters on the drawing representing like parts.

This invention relates to that type of fluid gage for indicating thefluid level in a tank in which the indication is made by a magneticneedle, the position of which is controlled by a magnet that in turn hasits position controlled by a float. A fluid gage of this't-ype is shownin my Patents No. 794,675 and No. 794,676, dated July 12, 1905. 1n thesepatents, however, the fluid gage is associated directly with the tankcontaining the liquid the-level of which is to be indicated.

My present invention aims to pro-vide a -novel fluid gage of theabove-described character which can be located at a point remote fromthe tank and which will at all times indicat-e the level of the liquidin the tank. While a fluid gage embodying my invention is capable foruse in a variety of locations, it is especially applicable for use inconnection with automobiles for indicating the level of the gasolene inthe gasolene tank because it is possible with my invention to place theindicator or gage on the dasher or in some other position where it canbe readily seen by the occupant of a car, while the gasolene tank itselfmay be under the seat or in any other convenient location.-

My invention also aims to provide anovel construction of head for thegage, by' ineans of which the dial and the indicatin needle may beplaced at an angle to the axis ofthe float shaft2 thus making a gagewhich can be more readily read than if the dial stood in a horizontalplane. y

My invention also aims to provide a novel construction whereby slightdifferences in level of fluid in the tank can be readily read on theindicator, and to otherwise improve the gage in features which will bemore fully hereinafter described and then pointed out in the appendedclaims.

1n the drawings wherein lt have illustrated some embodiments of myinvention, Figure 1 is a side view of an automobile showing my improvedgage applied to the ,dasherg Fig. 2 is a vertical section through a.gage embodying my invention; Fig. 3 is a top plan view of the gage head;Fig. 4 is a section on the line Fig. 2;Fig 5 is a detail of a modifiedform of gage; Fig. 6 is a vertical section through a. head showing agage of that type which is adapted to indicate small variations in fluidlevel; Fig. 7 is a plan view of the head shown in Fig. 6. Fig. 8 is adetail view showing a different manner of suspending the float shaft.

1n the automobile shown in Fig. 1, 3 indicates the gasolene tank, itbeing situated under the scat. The ga e for indicating the level ofgasolene in sai tank is designated generally by 4. 1t is shown as placedon the dasher 5 in a position where it may be readily read by anoccupant of the car. As

stated above, the gage is of that type shown' in my Patents No. 794,675and No. 794,67 6, both dated July 12, 1905, in which' a float controlledby variations in liquid level is used to actuate a sha-ft sustaining amagnet which controls the position of a magnetic needle constituting theindicating finger. The magnet of the gage is shown at 6 and it issustained by a ribbon shaft 7 which extends through a float 8 that isreceived in a tube 9 provided with a spiral slot 11, said float havingarms 10 extending-therefrom which play in said' slot 11. As the lioatrises and falls, the shaft, and consequently the magnet 6, will beturned, as will be clearly understood` The gage is also provided with ahead 12 in which is pivoted a pointer or indicator 13 that plays over arally-slotted tube 9 in `a casing 15 which forms a closed chamber and Iestablish a1 'the bottom of the tank, as' clearly seen in Fig. 1. Theposition of the float 8 and consequentlythe position of the pointer orneedle 13 is controlled by the level of the liquid marks 21. When the inthe casing 15, and as the liquid level in said casing is always the sameas that in -the tank 3, the gage will, when setup as shownl in Fig. 1,properly indicate the level of the liquid in the tank 3.

The communication between the casing 15 and the tank 3 may be providedfor in a variety of ways. Where the tank is not under pressure, it issucient to connect the bottom of the casing 15 .with the bottom of thetank by a pipe or conduit 16. If, however, the tank is under pressure,ythen it lwould be necessary to provide for equalizing the pressure inthe casing 15 and in the tank, and I propose to accomplish this byforming a double connection between the casing 15 and the tank, as shownin Fig. 5. rIhe pipe 16 will connect the bottom ofthe casing l5 with thebottom of the tank and another pipe 17 will communicate with the top ofthe tank 3 and will communicate also with a pipe 18 which extends up inthe casing 15 to the top thereof. The pipes 17, 18 serve to equalize theair pressure between the casing and the tank, as will be obvious.

In my 'improved ga I have so marked the dial 14 that the pointer 13 willnot only indicate the depth of gasolene in the tank, but will-.also`present to the observer what practically amounts to a reproduction ofthe shape of the tank'so that the observer may see for himself therelation between the body of gasolene in the tank and the size of thetank. I accomplish this by placing on the dial a geometricalfigureysimilar to the vertical cross-'sectional shape of the tank, said figurehaving such a position relative to the pointer or needle 13 that theposition of the needle will `not only indicate whether the tank isonefhalf full, three quarters full, etc., but will also indicate therelative posi- [tion of the fluid level to the bottom of the tank... Inthe drawings herein shown the tank is substantially'l square in crosssection and the dial 14 has thereon lines 20 which are arranged toconstitute a square. One of the lines representing the vertical side ofthe tank is provided with graduation pointer 13 poi-nts to anyone of thegraduatmn marks, this indicates 'that the luid'level has the samerelation to the bottom of the tank 3 that said indication mark has tothe lower side of the square 20. If the tank is circularin crosssection, then a circle will be formed on the dial, or if thetank has anyother cross sectional shape, a geometrical figure having a smaller shapewill' 'be formed on the dial. In any case, this construction not onlyindicates'to the observer the depth of the gasolene in the tank, butalso enables him to compute the relative amount of gasolene.

lWhere the gage is placed on the dasher, as above described,it can bemore readily read if the dial is inclined slightly rather than placed ina horizontal position. In Fig; 2 I have shown how this may be donewithoutedisturbing the proper operative relation between the needle 13and the magnet 6. In the embodiment shown. in Fig. 2, the magnet 6isreceived within a-chamber 25 formed in a block 26, said block havingthe annular flange 27. to which the tube 9 and casing 16 arescrew-threaded. The upper surface 28 of'this block is inclined and thehead 1 2 sets on this upper surface. The magnet 6 is provided with thebeveled end 29 which stands substantially parallel 'with the dial 14 orthe magnetic needle 13. The strength of the magnet is such that theneedle 13 will follow the position of the magnet even though said needleoperates about an aXis situated at an angle to the aXis of the magnet.The head 12 is preferably made detachable from the block 26 and meansare provided for locking the needle from rotation automatically when thehead is removed. The means employed for this purpose may be the same asis shown and described in my Patent Number 903,213, dated November 10,1908. The needle 13 is provided with a hub 30 which is normally situatedbetween two spring arms 31. These arms normally engage the hub and holdthe needle from rotation. When, however, ythe head is applied to theblock 26, a pin or pins 32 extending from said block engage the springarms and disengage them from the hub, thus permitting the pointer torotate Lfreely.

It is sometimes desirable to be able to note very small changes in uidlevel in the tank 3, but where the pointer only makes a half revolutionbetween the full and the empty positions, a slight change in level willchange the position of ,the pointer so slightly that it would be veryv`diiicult to detect it. In Figs. 6 and 7 I have shown a form of headfor a gage in which very slight variations in the liquid level may beeasily detected. In this embodiment of my invention the magnet 6 hasrigid therewith a gear wheel 40 which meshes with a smaller ear wheel 41that carries-a. magnet 42.3T e magnet 7 operates the pointer or magneticneedle 13 in usual manner. Situated above the magnet 42 is a smallermagnetic needle 43, said needle being mounted on a suitable pivot 44.Owing to the fact that the pinion 41 is very much smaller than thepinion 40, a slight turning movement of the gear will turn the gear 41through a considerable angle. The magnetic needle 43 varies the positionof the magnet 42 and therefore any slight turning of the gear 40 andmagnet Z will be indicated by the turning of the magnetic needle 43through a considerable angle. rThe Vrelation between the magnetic needle43 and the magnetic needle 13 is somewhat analogous to that between theminute and the second hands of a'watch, although, of course, the gearingconnecting the magnets is timed very differently from that connectingthe minute and second hands of a watch. In order that the magneticneedles may not interfere with the .operation of each other, I prefer tomake the long magnetic needle 13 with its central portion only ofmagnetizable material, as shown at 50, such central portion being onlysubstantially as longl as the magnet 7 The extremities of the needle 13may be made of anyA known non-magnetic material which will not influencein any way the needle 43.

The ribbon shaft 7 may be suspended in a variety of ways withoutdeparting from the invention, although under some conditions I- preferthe manner of suspending it shown inl Fig.4 8. In this embodiment, saidribbon shaft has secured thereto at its upper end a short length oftubing 61 on the upper end of which is mounted a magnet 6, The shaft issuspended by means of a cord 62.preferably.of silk which extends downthrough the'tube '61 and the lower end of which extends through anopening 63 formed in the ribbon shaft and is-provided with a knot 64 toprevent it being pulled through said opening. The upper end of the cordextends through an opening in the block 26 which is shown in Fig. 8, orthrough an opening in the plate at the upper end of the tube 9, and saidupper end of the cord is provided with a knot 65 by` which the cord issustained. This construction makes a very flexible suspension for theshaft which permits the shaft to turn freely and vwithout friction.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patentis:-'

1. In a gage, the combination with a casing, of a spirally slotted tubeinclo'sed within the casing, a shaft or support within the tube, a floatmovable longitudinally of the shaft vbut held from rotation relativethereto and provided. with a' laterallyfextended pin which plays -insaid slot, a pointer, and

means to operate the latter by the turning movement of the shaft.

2. In a gage, the combination with a head block, of a casing securedthereto, means to connect said casing with the tank having the liquid.therein the level of which is to be indicated, a spirally-slotted 'tubealso -secured to said head block and situated within said casing, afloat within said tube and guided by the slot therein, a pointersustained by the head block, and means to operate the pointer by theturning of the oat caused by the rising and falling movement thereof. l

3. In a gage, the combination with a magnet, of a shaft sustaining saidmagnet, a float, means to turn the shaft by the rising and fallingmovement of the float, a magnetic needle controlled as to its positionby the magnet, and means to sustain said needle with its axis at anangle to the axis of the magnet.

4. In a gage, the combination with a head block, of a tube dependingtherefrom, a shaft within said tube, a magnet sustained by the shaft, aoat within the tube, means coperating with the tube to turn the shaft bythe rising and falling movement of the float, said block having aninclined upper face, a gage head sustained by said face, and a magneticneedle journaled in said head with its axis at an angle to the axis ofthe magnet.

5. In a fluid gage, the combination with a spirally-slotted tube, of afloat shaft within said tube, a loat movable longitudinally of saidshaft and provided with an .arm extending into the slot in the tube, anda cord for pivotally suspending said shaft from the upper end of thetube.

6. In a fluid gage, the combination with a spirally-slotted tube, of afloat shaft within said tube, a float movable longitudinally of saidshaft and provided with an arm extending into the slot in the tube, atube secured to the upper end of said shaft, a magnet carried by saidtube, and a cord secured to said shaft and extending through said tubeand by which the shaft is pivotally suspended.

7. In a gage, the combination with a head block having an annular flangeon its under side, of a casing secured to the exterior of said flange,means to connect said casing to a tank, a spirally-slotted tube securedto the interior of said ange, a float within said tube provided with apin to enter the slot of the tube, a pointer carried by the headblock,and means to operate the pointer by the turning of the float caused bythe rising and falling movement thereof.

8. In a gage, the combination with a casing provided with means forconnection to a tank, of a float within the casing, a pointer sustainedby the casing, means to operate pointer will indicate thereon the depthof the liquid in the tank.

In testimony whereof, I have signed my name to this specification,` inthe presence of two subscribing Witnesses.

MORRIS MARTIN.

Witnesses LOUIS C.SM1TH, THOMAS J. DRUMMOND.

